PyroCb in Russia

On 22 August there was a pyroCb in Russia. This pyroCb formed at 52.7 N 108 E at 05:00 UTC. Himawari-8 detected the smoke plume and clouds around the fires, as well as the fire hot spots. Starting at 04:30 UTC on August 22, the animation below shows visible (.64 μm) on the left and shortwave IR (3.9 μm) on the right (click image to play animation). In the shortwave IR images the darker black to red pixels indicate very hot IR brightness temperatures exhibited by the fire source region.

Himawari-8 0.64 μm visible (left) and 3.9 μm shortwave IR (right) images (click to play animation)

Himawari-8 0.64 μm visible (left) and 3.9 μm shortwave IR (right) images (click to play animation)

In addition, using Himawari-8 10.4 μm IR channel imagery the minimum cloud-top IR brightness temperatures could be found. The animation below, starting at 04:30 UTC on 22 August, shows that the pyroCb reached around -56 ºC (orange color enhancement) at 8:10 UTC.

Himawari-8 10.4 μm IR images (click to play animation)

Himawari-8 10.4 μm IR images (click to play animation)

To further investigate the transport of smoke from this fire CALIPSO was used. This LIDAR shows the height of the clouds from the wildfire. The first image below is the 532nm Total Attenuated Backscatter plot on 22 August from 19:07 UTC to 19:30 UTC. The smoke from this fire can be seen around 52.2 N indicated by a red color with a height of 12 km. The second image is 1064 nm Total Attenuated Backscatter plot, the smoke on this plot is indicated by a green color. The third image is the Depolarization image the smoke is indicated by a light blue color. The fourth image is the Attenuated Ratio plot between 1064 nm and 532 nm. The smoke is indicated by the magenta pixels. The fifth image is the Vertical Feature Mask. This plot shows the different features that are in the atmosphere, the smoke is attributed as a cloud on this plot and is indicated by a light blue color. The last image shows the subtype of the aerosols that have been detected by the LIDAR. This shows that the aerosols that the LIDAR has detected are smoke (indicated by the black pixels) around 52 N.

CALIPSO 532 nm Total Attenuated Backscatter on 22 August (click to enlarge)

CALIPSO 532 nm Total Attenuated Backscatter on 22 August (click to enlarge)

 

CALIPSO Depolarization Ration on 22 August (click to enlarge)

CALIPSO Depolarization Ration on 22 August (click to enlarge)

CALIPSO 1064 nm Total Attenuated Backscatter on 22 August (click to enlarge)

CALIPSO 1064 nm Total Attenuated Backscatter on 22 August (click to enlarge)

CALIPSO Attenuated Color Ratio between 1064 nm and 532 nm on 22 August (click to enlarge image)

CALIPSO Attenuated Color Ratio between 1064 nm and 532 nm on 22 August (click to enlarge image)

CALIPSO Vertical Feature Mask on 22 August (click to enlarge image)

CALIPSO Vertical Feature Mask on 22 August (click to enlarge image)

CALIPSO Aerosol Subtype plot on 22 August (click to enlarge image)

CALIPSO Aerosol Subtype plot on 22 August (click to enlarge image)

Below is an animation of the convergence at 250 mb shown by a color fill, the the 250 mb geopotential height contoured every 30 meters and the wind barbs. It has been investigated that upper level divergence is associated with the ability for pyroCu to turn into a pyroCb (Peterson et al., BAMS, Feb. 2015, 229-247). Starting at 0 UTC on 22 August the spot of the pyroCb is indicated by a white dot. This pyroCb is in an area of divergence. This is conducive to the strengthening of the pyroCb. If there is divergence at upper levels there is rising air below that area of divergence. These conditions are favorable to the pyroCb developing.

250 mb Convergence(color fill), Geopotential Height (contoured every 30 m) and wind barbs every 6 hours starting on 22 August 0 UTC.

This Skew-T taken at 6 UTC on 22 August after the pyroCb formed shows a very dry layer around 500 mb. From the Skew-T it is apparent that there is a lot of CAPE which is favorable for convective development. This will help turn pyroconvection into a pyroCb. Furthermore, from the Skew-T the winds are veering indicating a cyclonic motion.
822skewt Skew-T at 6 UTC (click to enlarge) Green line is dew point and red line is temperature.

 

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